Historical Polymarket order book API — archived L2 bid/ask depth, outcome prices, and liquidity metrics for crypto and sports prediction markets.
Website · API · Docs · Quickstart · Pricing
PolyOrderbooks stores historical Polymarket market data so you can replay past order books — not just live snapshots or mid prices.
- L2 order books — full bid/ask ladders as
[price, size]per outcome - 250ms capture — every open market, on every plan, including Starter
- Prices & metrics — outcome prices, volume, liquidity, spread on the same window
- Discovery — search series, events, and markets (crypto and sports)
- Resolved markets — settled markets stay queryable, including the winner
- Read-local API — your client calls our archive; read paths never hit live Polymarket
- Backtesting — fill simulation and slippage against real captured ladders
Verifiable and citable: 1B+ L2 snapshots across 800k+ markets, published as a CC BY 4.0 dataset with a Zenodo DOI (10.5281/zenodo.22084114).
export POLYORDERBOOKS_API_KEY="pob_your_key_here"
curl -s -H "X-API-Key: $POLYORDERBOOKS_API_KEY" \
"https://api.polyorderbooks.com/v1/markets?search=bitcoin&limit=5"Create a free API key: polyorderbooks.com/signup
| Repository | What it is |
|---|---|
| polyorderbooks-python | Official Python client — pip install polyorderbooks |
| polyorderbooks-backtest-python | Replay-accurate backtesting library — pip install polyorderbooks-backtest |
| backtest-strategies | Runnable strategy cookbook for backtesting against real L2 order books |
| mcp-server | MCP server for Claude, Cursor, and other MCP clients — @polyorderbooks/mcp-server |
| Repository | What it is |
|---|---|
| python-examples | Runnable examples for the Python SDK |
| n8n-templates | n8n workflows for historical order book data |
| polymarket-orderbook-research | Reproducible measurement scripts behind the published research |
- Email: contact@polyorderbooks.com
- X: @polyorderbooks
Independent data product. Not affiliated with or endorsed by Polymarket.